Today, there are over four-thousand privately issued currencies in more than 35 countries. These include commercial trade exchanges that use barter credits as units of exchange, private gold and silver exchanges, local paper money, computerized systems of credits and debits, and digital currencies in circulation, such as digital gold currency.
issue paper money. States, municipalities, private banks, railroad and construction companies, stores, restaurants, churches and individuals printed an estimated 8,000 different types of money by 1860. If an issuer went bankrupt, closed, left town, or otherwise went out of business the note would be worthless. Such organizations earned the nickname of "wildcat banks" for a reputation of unreliability; they were often situated in remote, unpopulated locales said to be inhabited more by wildcats than by people. The National Bank Act of 1863 ended the "wildcat bank" period.
Since 1991, residents of and around the city of Ithaca in Western New York State have been using a private currency in which participating workers either earn or purchase Ithaca Hours, which may be used to buy goods and services locally. The system has been ruled legal provided all Hours-derived revenues are reported to the IRS as income.
BerkShares is a local currency that circulates in The Berkshires region of Massachusetts. It was launched on September 29, 2006 by BerkShares Inc., with research and development assistance from the E. F. Schumacher Society. The BerkShares website lists over 370 businesses in Berkshire County that accept the currency. In 30 months, 2.2 million BerkShares have been issued from 12 branch offices of five local banks.
United States Private Dollars
In 2007, Angel Cruz, founder of The United Cities Corporation (TUC), announced he was establishing an alternative "asset based" currency named "United States Private Dollars". Cruz claimed his "United States Private Dollars" were "backed by the total net worth of the assets of its members" and had printed $6,127,379,895 worth of the private currency. According to a press release, these assets were $357,170,993,418. The currency featured the slogan "In Jehovah We Trust".
Several of Cruz's employees stated that they had been promised a 30-year contract, a new car, health insurance and payment of their debts. The workers received compensation in the form of checks from United Cities. Those checks were rejected as fraudulent by local banks after the employees deposited them because they lacked standard routing numbers.
On July 8, 2007, Cruz attempted to evict employees of a Palmetto Bay, Florida branch of the Bank of America. He was accompanied by 30 of his followers, 10 of whom were dressed as armed guards, and he presented a "court order" supposedly issued by "The United Cities Private Court." The "court order" referenced a pending $15.25 billion lawsuit against the Bank of America filed by Cruz in Miami-Dade County Court the month before. Cruz had claimed the bank had wronged him because an Orlando branch of Bank of America refused to cash $14.3 million in United Cities "bank drafts."
On August 6, 2008, Cruz was indicted by a Federal grand jury in Florida on one count of conspiracy to defraud the United States under 18 U.S.C. § 1344 and 18 U.S.C. § 371 and six counts of bank fraud under 18 U.S.C. § 1344 and 18 U.S.C. § 2 in connection with his dealings with Bank of America with the United Cities bank drafts. If convicted, Cruz would face a maximum possible sentence of up to 185 years in federal prison.
As of late October 2010, the Assistant United States Attorney in Orlando, Florida filed a report with the U.S. District Court to the effect that Angel Cruz was still a fugitive, and that the United States Secret Service was continuing its efforts to apprehend Cruz. A co-defendant in the case, Harry William Marrero, was sentenced on September 1, 2009 to eight years and one month in prison. Marrero is incarcerated at the United States Penitentiary at Atlanta, Georgia, and with time off for good behavior would be scheduled for release on September 7, 2015.
The Liberty Dollar was a commodity-backed private currency created by Bernard von NotHaus and issued between 1998 and 2009, when von NotHaus and others were indicted on federal charges related to its issue. In 2011 von NotHaus was pronounced guilty of "making, possessing, and selling his own currency".
Now, s44(1) of the Reserve Bank Act 1959 prohibits this practice. In 1976, Wickrema Weerasooria published an article which suggested that the issuing of bank cheques violated this section, though some banks responded that since bank cheques were printed with the words "not negotiable" on them, the cheques were not intended for circulation and thus did not violate the statute. Many other nations have similar such policies to eliminate private sector competition.
One example of a currency that lost government support but retained use in a community is the Iraqi Swiss dinar.
England has had the Totnes pound since it was launched by Transition Towns Totnes Economics and Livelihoods group in March 2007; A Totnes Pound is equal to one pound sterling and is backed by sterling held in a bank account. As at September 2008, about 70 businesses in Totnes were accepting the Totnes Pound. Other local currencies launched since then include the Lewes Pound (2008), the Brixton Pound (2009), the Stroud Pound (2009) and the Bristol Pound, which also allows for electronic payments 
Since starting in 2006, the "City Initiative Karlsruhe" has issued the Karlsruher which has no nominal value. Every coin has the value of 50 Eurocents and is primarily used in parking garages. As of 2009, 120 companies in Karlsruhe accept the Karlsruher and usually grant a discount when paid with it.
In Canada, private currencies cannot be referred to as being legal tender (e.g. Calgary Dollar and Toronto dollar), or use alternate names like coupon or bucks (such as Canadian Tire money and Pioneer Energy's Bonus Bucks).
In August 2013, the German Finance Ministry characterized Bitcoin as a unit of account, usable in multilateral clearing circles and subject to capital gains tax if held less than one year.
In Thailand, lack of existing law leads many to believe Bitcoin is banned.
A cryptocurrency is a form of digital currency where cryptography to secure the transactions and to control the creation of additional units of the currency. The cryptographic systems used allow for decentralisation; a decentralised cryptocurrency is fiat money but one without a central banking system.
On 6 August 2013, Federal Judge Amos Mazzant of the Eastern District of Texas of the Fifth Circuit ruled that bitcoins are "a currency or a form of money" (specifically securities as defined by Federal Securities Laws), and as such were subject to the court's jurisdiction, and Germany's Finance Ministry subsumed Bitcoins under the term "unit of account"—a financial instrument—though not as e-money or a functional currency, a classification nonetheless having legal and tax implications.